The present invention relates to catheters of the type used in medical applications. In particular, the invention relates to multi-lumen catheters.
A multi-lumen catheter is used in medical applications which require more than one lumen for introducing medication or other fluids into a patient and/or removing blood from a patient at the same time. Typically, multi-lumen catheters, when viewed in cross-section, appear to be circular and to have lumen walls which extend radially from the center of the circle.
Accordingly, a triple lumen catheter would appear in cross-section like a pie which has been cut into three portions (which are not necessarily equal in size). This appearance results from the fact that catheters are typically manufactured out of plastic by an extrusion process. The distal end of a multi-lumen catheter is typically sealed, and side holes are formed near the distal end into each of the lumens. As a result, the side holes of any one of the lumens are all within a given segment of the arc defined by the interior walls and the outside circumference of the catheter. As a result of this configuration, it is possible that the side holes of one lumen can be wholly or partially occluded by the interior wall of a patient's vessel when the catheter has been inserted.